(4 of )Cleveland Browns defensive back K'Waun Williams walks off the field after the Baltimore Ravens defeated the Browns 33-27 in an NFL football game, Monday, Nov. 30, 2015, in Cleveland. (AP Photo/Ron Schwane)

(5 of )New York Giants' Robbie Gould (5) kicks a field goal during the second half of an NFL football game against the Dallas Cowboys on Sunday, Dec. 11, 2016, in East Rutherford, N.J. (AP Photo/Bill Kostroun)

(6 of )Washington Redskins' Pierre Garcon takes the field before the first half of an NFL football game against the Philadelphia Eagles, Sunday, Dec. 11, 2016, in Philadelphia. (AP Photo/Matt Rourke)

(7 of )Buffalo Bills wide receiver Marquise Goodwin (88) celebrates his touchdown, during the second half of an NFL football game against the Miami Dolphins, Sunday, Oct. 23, 2016, in Miami Gardens, Fla. To the right is Buffalo Bills defensive tackle Leger Douzable (91). (AP Photo/Lynne Sladky)

(8 of )Oakland Raiders linebacker Malcolm Smith (53) warms up before an NFL football game against the Carolina Panthers in Oakland, Calif., Sunday, Nov. 27, 2016. (AP Photo/Marcio Jose Sanchez)

(9 of )New England Patriots wide receiver DeAndre Carter (13) go out for a pass during an NFL football practice Tuesday, June 7, 2016, in Foxborough, Mass. (AP Photo/Steven Senne)

(11 of )Seattle Seahawks middle linebacker Brock Coyle (52) reacts during the second half of an NFL football game against the New York Jets Sunday, Oct. 2, 2016, in East Rutherford, N.J. (AP Photo/Kathy Willens)

(14 of )Atlanta Falcons' Aldrick Robinson (19) during warm-ups before an NFL football game against the Carolina Panthers in Charlotte, N.C., Saturday, Dec. 24, 2016. The Falcons won 33-16. (AP photo/Bob Leverone)

(15 of )Chicago Bears quarterback Matt Barkley prepares to throw a pass during the first half of an NFL football game against the Minnesota Vikings, Sunday, Jan. 1, 2017, in Minneapolis. (AP Photo/Jim Mone)

Grant Cohn: Grading the 49ers' roster moves in free agency

The 49ers have signed 15 free agents so far this offseason. What will these players bring to the team, and what won’t they bring?

Let’s grade each signing.

1. FB Kyle Juszczyk — 4 years, $21 million.

I love this one. Juszczyk is the best fullback in the NFL and will be just 26 years old this season — the Niners can build their offense around him now and in the future. And not just their run offense. Juszczyk doesn’t only block and run. He caught 78 passes for the Baltimore Ravens the past two seasons. He will become Kyle Shanahan’s version of Tom Rathman.

Grade: A-plus.

2. WR Jeremy Kerley — 3 years, $8.4 million.

Kerley is only 5-foot-9, but he’s extremely quick, he has great hands and he makes tough catches over the middle. He was the 49ers’ best receiver last season. And he’s still only 28. So, he’ll be around if and when the 49ers become a good team. I thought they wouldn’t re-sign him because he doesn’t know Shanahan’s complicated system, but the 49ers recognized Kerley’s talent and potential. Good for them.

Grade: A.

3. WR Aldrick Robinson — 2 years, $4 million.

Robinson played for Shanahan last season on the Falcons and averaged 16.2 yards per catch. He’s a cheap, young backup receiver who can teach Shanahan’s system to receivers who aren’t familiar with it. But he’s more than a mentor. He’s a legitimate deep threat. Against the 49ers last season, he gained 111 receiving yards on four catches.

Grade: A-minus.

4. QB Matt Barkley — 2 years, $4 million.

I’m surprised the Bears let Barkley go this offseason. He might be better than the quarterback they replaced him with — Mike Glennon, the $45 Million Man. Barkley started six games in 2016 and played well, particularly against the 49ers, a game he won, and against the Packers, a game in which he made only three bad throws. He’s young and improving. I expect he’ll finish the season as the 49ers starter.

Grade: B-plus.

5. QB Brian Hoyer — 2 years, $12 million.

Hoyer will go into the season as the 49ers’ starting quarterback. He turns 32 in October, and he has an extensive injury history — those are his drawbacks. He probably doesn’t have a future with the team. But, he’s a good addition for two reasons: One, he played for Shanahan in 2014 and can help teach his system to the rest of the players on offense. And two, signing Hoyer means the Niners probably won’t trade their first-round pick to Washington for Kirk Cousins. That trade would have been a disaster. The Niners need their first-round pick. Plus, they can sign Cousins next year — he’ll be a free agent. They don’t have to trade for him. The Niners passed that test.

Grade: B.

6. LB Brock Coyle — 2 years (terms not yet released).

A solid special-teams player and a backup linebacker with experience playing in the defensive scheme the 49ers will run next season. Coyle even started three games at linebacker last season for the Seahawks. Decent signing.

Another solid special-teams player. Jones is a backup safety with no experience playing in the defensive scheme the 49ers will run next season. He will make the final roster if the Niners don’t select a safety in the upcoming draft.

Grade: C-plus.

8. WR DeAndre Carter — 2 years (terms not yet released).

A kick-returner and a backup wide receiver who has never been on an NFL active roster — Carter has been on three teams’ practice squads since the Baltimore Ravens signed him as an undrafted free agent in 2015. He most likely will be a practice-squad player for the 49ers. And that’s OK. Teams need practice-squad players.

Grade: C.

9. TE Logan Paulsen — 1 year, $1 million.

A blocking tight end who caught only three passes last season and turned 30 in February. Not the kind of player a rebuilding team should sign, especially when younger blocking tight ends are easy to find. Rebuilding teams should look to the future. But, signing Paulsen makes some sense. He played for Shanahan in Washington and can vouch for the rookie head coach and help him win over the 49ers locker room. That’s where Paulsen will make his biggest impact.

Grade: C-minus.

10. CB K’Waun Williams — 1 year, $690,000.

Williams was an undrafted free agent in 2014 who made the Cleveland Browns roster as a rookie. He immediately became their starting nickelback and played well for the most part. But, he couldn’t stay healthy. Last season, he missed 16 games with an ankle injury, and the previous two seasons he suffered two concussions, two hamstring injuries, two shoulder injuries and an abdominal injury. It’s strange a rebuilding team would sign a player who already is breaking down. At least he’s cheap.

Grade: D-plus.

11. PK Robbie Gould — 2 years, $4 million.

Another cheap signing. Gould was an excellent kicker four years ago. Now, he’s 35. Last season, he played in only 10 games for the New York Giants after the Chicago Bears cut him, and missed three of 23 extra points. The Giants made no effort to re-sign Gould this offseason. But the Niners eagerly gave him a two-year deal. Bad move. Gould is shot. They should have signed someone younger and better.

Grade: D.

12. DT Earl Mitchell — 4 years, $16 million.

Mitchell is a nose tackle who turns 30 in September. He missed 12 games the past two seasons with an injured calf. When asked recently on a conference call if his calf will be an ongoing issue for him, Mitchell said, “It’s definitely something that I work on.” Yikes. What is the 49ers’ fascination with broken down 30-year-olds? Are they the cornerstones of a rebuilding team? I don’t think so.

Grade: D-minus.

13. WR Marquise Goodwin — 2 years, $6 million.

A former third-round pick who turns 27 in November and is one of the fastest wide receivers in the NFL. Sounds like someone who would be expensive to sign. But he was cheap, because he’s injury prone. Goodwin has missed 40 percent of his games since the Bills drafted him in 2013. He injured his wrist, hand, elbow, ribs, hamstring, knee, calf and ankle, and he had two concussions. And he was a backup. Now he’s in line to start for the 49ers. What else could possibly go wrong?

Grade: F-plus.

14. WR Pierre Garçon — 5 years, $47.5 million.

Garçon is a tough possession receiver — think Anquan Boldin, except Garçon scores fewer touchdowns. He’s a solid No. 2 receiver. Problem is, the Niners paid him as if he’s a No. 1 receiver, plus he turns 31 in August. He’s on the downside of his career and probably won’t be a factor when the 49ers are ready to compete a few years from now. So, what was the point of signing of Garçon? Was it to make the 49ers a more respectable last-place team? Or was it was to help teach Shanahan’s system to the younger receivers — Garçon played for Shanahan four years ago. If the Niners signed Garçon to be a mentor, he’s an expensive one. And a redundant one. Aldrick Robinson can teach Shanahan’s system, and Robinson is cheap. The Niners should have given Garçon’s contract to someone else.

Grade: F.

15. LB Malcolm Smith — 5 years, $26.5 million.

Smith will play either alongside NaVorro Bowman or will replace Bowman if he never recovers from his torn Achilles tendon. Smith is no Bowman, though. Smith should be a backup. The past two seasons, he was a starter for the Raiders and he was awful — couldn’t stop the run or cover anyone in the pass game. The Raiders had enough of him, so they let him go. Didn’t even have a replacement. Just got rid of him. But, the 49ers paid him big money to be a key contributor. This was their worst signing.

Grade: F-minus.

Rookie General Manager John Lynch and rookie head coach Kyle Shanahan made some questionable deals, but also made some smart ones. Not bad for their first offseason. They’re showing promise, learning on the job.

Grant Cohn writes sports columns and the “Inside the 49ers” blog for The Press Democrat’s website. You can reach him at grantcohn@gmail.com.